title: Interleukin and neurotrophin up-regulation correlates with severity of H1N1 infection in children: a case-control study.
abstract: OBJECTIVE
  To evaluate the correlation between cytokine and neurotrophin expression and clinical findings, disease severity, and outcome of children with H1N1 influenza infection.
  
  
  METHODS
  A prospective observational clinical study was performed on 15 children with H1N1 infection, 15 controls with lower respiratory tract infections (LRTI), and 15 non-infected children. Plasma levels of interleukin (IL)-1β, IL-6, and neurotrophic factor (nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and glial derived neurotrophic factor (GDNF)) were measured using immunoenzymatic assays.
  
  
  RESULTS
  Significantly higher levels of IL-1β, IL-6, BDNF, and NGF were detected in patients with H1N1 infection compared to LRTI controls, while there was no significant variation in GDNF in the two groups. IL-1β, IL-6, BDNF, and NGF levels were significantly higher in H1N1 patients with more severe clinical manifestations compared to H1N1 patients with mild clinical manifestations. Of note, IL-6 was significantly correlated with the severity of respiratory compromise and fever, while NGF up-regulation was associated with the duration of cough. No correlation was found between interleukin and neurotrophic factor expression and outcome.
  
  
  CONCLUSIONS
  H1N1 infection induces an early and significant IL-1β, IL-6, BDNF, and NGF up-regulation. The over-expression of these molecular markers is likely to play a neuroimmunomodulatory role in H1N1 infection and may contribute to airway inflammation and bronchial hyper-reactivity in infected children.
authors.affiliation: Department of Pediatrics, Catholic University of the Sacred Heart, A. Gemelli Hospital, Largo Gemelli, 1, 00168, Rome, Italy. Electronic address: achiaretti@yahoo.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Chiaretti
authors.forename: Silvia
authors.initials: S
authors.lastname: Pulitanò
authors.forename: Giorgio
authors.initials: G
authors.lastname: Conti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Barone
authors.forename: Danilo
authors.initials: D
authors.lastname: Buonsenso
authors.forename: Luigi
authors.initials: L
authors.lastname: Manni
authors.forename: Domenico
authors.initials: D
authors.lastname: Capozzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Ria
authors.forename: Riccardo
authors.initials: R
authors.lastname: Riccardi
mesh_terms: D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000097:blood* / Q000175:diagnosis; D007378:Interleukins / Q000097:blood*; D063868:Patient Outcome Assessment; D011134:Polysaccharides / Q000097:blood*; D011446:Prospective Studies; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D016207:Cytokines; D007378:Interleukins; D011134:Polysaccharides; C010491:neurotropin
keywords: Brain derived neurotrophic factor; Glial derived neurotrophic factor; H1N1 influenza; Interleukins; Nerve growth factor